Communication devices such as User Equipments (UEs) are also known as e.g. mobile terminals, wireless terminals and/or mobile stations. A user equipment is enabled to communicate wirelessly in a cellular communications network, wireless communications system, or radio communications system, sometimes also referred to as a cellular radio system or cellular network. The communication may be performed e.g. between two user equipments, between a user equipment and a regular telephone and/or between a user equipment and a server via a Radio Access Network (RAN) and possibly one or more core networks, comprised within the cellular communications network.
The user equipment may further be referred to as a mobile telephone, cellular telephone, laptop, Personal Digital Assistant (PDA), tablet computer, surf plate, just to mention some further examples. The user equipment in the present context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data, via the RAN, with another entity, such as another user equipment or a server.
The cellular communications network covers a geographical area which is divided into cell areas, wherein each cell area being served by a base station, e.g. a Radio Base Station (RBS), which sometimes may be referred to as e.g. “eNB”, “eNodeB”, “NodeB”, “B node”, or BTS (Base Transceiver Station), depending on the technology and terminology used. The base stations may be of different classes such as e.g. macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. A cell is the geographical area where radio coverage is provided by the base station at a base station site. By the base station serving a cell is meant that the radio coverage is provided such that one or more user equipments located in the geographical area where the radio coverage is provided may be served by the base station. One base station may serve one or several cells. Further, each base station may support one or several communication technologies. The base stations communicate over the air interface operating on radio frequencies with the user equipment within range of the base stations.
In some RANs, several base stations may be connected, e.g. by landlines or microwave, to a radio network controller, e.g. a Radio Network Controller (RNC) in Universal Mobile Telecommunications System (UMTS), and/or to each other. The radio network controller, also sometimes termed a Base Station Controller (BSC) e.g. in GSM, may supervise and coordinate various activities of the plural base stations connected thereto. GSM is an abbreviation for Global System for Mobile Communications (originally: Groupe Spécial Mobile).
In 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), base stations, which may be referred to as eNodeBs or eNBs, may be directly connected to one or more core networks.
UMTS is a third generation mobile communication system, which evolved from the GSM, and is intended to provide improved mobile communication services based on Wideband Code Division Multiple Access (WCDMA) access technology. UMTS Terrestrial Radio Access Network (UTRAN) is essentially a radio access network using wideband code division multiple access for user equipments. The 3GPP has undertaken to evolve further the UTRAN and GSM based radio access network technologies, for example into evolved UTRAN (E-UTRAN) used in LTE.
In the context of this disclosure, the expression downlink (DL) is used for the transmission path from the base station to the user equipment. The expression uplink (UL) is used for the transmission path in the opposite direction i.e. from the user equipment to the base station.
In a cellular communications network various services are provided, via base stations to user equipments being served in the cells thereof, such as voice communication services and data services available on or via the Internet, or other local data networks. The data services may be services available on the World Wide Web (WWW), typically accessible to a user equipment via a web browser application installed thereon, or data services that are available via other protocols and/or relevant only to more specific applications or software installed on the user equipment. Using such data services involves download of digital content to the user equipment. Certain parts of the cellular communications network are responsible for identifying user equipments that request such data services and then makes sure that the service is provided to the user equipment via the base station serving the user equipment, preferably in such way that the user of the user equipment does experience any negative impact from the fact that the service is provided via the cellular communications network. For example, a user that uses an application executing on a user equipment, e.g. a web browser, for accessing digital content on the Internet, simply wants the access without having to care of, or be negatively affected, by the fact that the connection is via the cellular communications network.
However, there are certain problems associated with the desire to provide such user experience. One problem is the fact the there is a limited bandwidth in each cell and thereby restrictions in how many user equipments that may be guaranteed a certain quality of service at the same time. By a continuously increasing number of user equipments and increasing usage of data services in cellular communications networks of today, the problem is becoming increasingly greater. Even if the overall capacity is increased there will still be a certain maximal amount of bandwidth available in each cell for the delivery of digital content for the data services, and there may be usage peaks where it would be desirable to provide digital content to user equipments in a cell at such amount and rate that would exceed the capacity of the cell. When this happens the result is a poor user experience, e.g. bad performance of the data service, errors in the digital content and/or data service, or even non-access to the requested digital content or non-availability of the data service.